Measurement of the homogeneous velocity of inclined oil-in-waterflows using a resistance cross correlation flow meter

Abstract

This paper describes an investigation into a cross correlationflow meter, using `global' resistance sensors, for measuring thehomogeneous velocity of inclined oil-in-water flows. The cross correlationflow meter measures the axial propagation speed Ucc of intermittentKelvin-Helmholtz structures in the flow. It is shown that, for inclinationangles in the range 15° to 45° from the vertical, themeasured velocity Ucc is dependent only upon the homogeneous velocityand is independent both of the inclination angle θ of theflow and of the oil volume fraction α. For an angle of inclinationto the vertical of 60°, Ucc is dependent both upon thehomogeneous velocity and upon the oil volume fraction α.For inclination angles in the range 15°⩽θ⩽45°predictions of the homogeneous velocity were obtained using only themeasured cross correlation velocity Ucc. For 15°⩽θ⩽45°, the mean percentage error Ē in the predicted homogeneousvelocity was 0.1% whilst the standard deviation S̄ of thepercentage error in the predicted values of the homogeneous velocity wasfound to be 4.0%. For the angle of inclination to the vertical of60° predictions of the homogeneous velocity were obtained using themeasured cross correlation velocity Ucc and the measured oil volumefraction α. For θ = 60° the mean percentage errorĒ in the predicted homogeneous velocity was -0.39% whilst thestandard deviation S̄ of the percentage error in the predictedvalues of the homogeneous velocity was 5.2%.